Inside, the luminosity of the stained glass fills the entire church.
The copper roof and mismatched towers are the hallmark of Chartres. The relation of the west front to the towers was altered in the previous Romanesque era due to the cathedral's unsteady foundations. The front was originally much farther back, but the foundations were unable to support it, so it was taken down, stone by stone, and moved forwards onto steadier ground creating flatness in the fazade. This architectural error, however, saved this part of the cathedral in the fire of 1194, as the vestibule formed an area of protection between the nave and the west front. .
The new cathedral's architect had to follow the foundations of the older Romanesque cathedral, which meant that the Gothic vaulting had to cover a space much larger than ever before. The impression of a weightless wall elevated above the nave is heightened by the lack of any visible feature in the interior technically capable of holding up a structure of this kind. The principle of its' construction lay in the disposal of internal technical means for supporting it. In order to solve this, the architect used flying buttresses, a system of supports on the outside, which alleviated some of the weight from the walls. The architect treated the buttresses in a highly original manner, stylizing the piers in a tower-like form, from which powerful arches spring over the side aisles to engage the nave wall. .
The main portal of Chartres is heavily decorated with an intricate congregation of carved figures. The pillar people are famous for their unique style. Although realistically the human forms sculpted into the pillars are inaccurate, elongated and compressed, this goes almost unnoticed due to attention to detail and to the human emotion expressed in the sculptures. .
The interior of Chartres Cathedral is no less impressive than the exterior. On entering, one can immediately see how the height and wide spacing of the arches and the shape of the piers that divide the nave from the aisles create the impression of magnificent power.
